1. Field of the Invention
The invention relates to the field of photo etching techniques.
Specifically, the invention relates to methods for producing photographic-print-quality image reproductions having a range of image contrast gradations throughout by an etching process.
In particular, the invention relates to the products produced by the etching techniques provided for by said methods.
2. Prior Art
The etching of glass and other materials to provide ornamented articles is well known in the prior art. Various means of producing images in glass and metals have been utilized. Typically, these variations depend upon the particular article of manufacture, the design or ornamentation desired, and the overall affect to be created.
Frederecici, U.S. Pat. No. 154,032; Bradley, U.S. Pat. No. 243,200; Stern, U.S. Pat. No. 322,864; Paini, U.S. Pat. No. 343,889; Freidrich, U.S. Pat. No. 1,205,728; Kueffel et al, U.S. Pat. No. 2,374,356; Maleyre, U.S. Pat. No. 2,530,436; and Becca et al, U.S. Pat. No. 3,759,753 teach various methods for defining an image on a surface. Such methods include the use of stenciling or other means of patterning a design upon an object, applying a protective resist substance and then etching the object.
Others skilled in the prior art have taught the use of photo resist materials, processed in either a positive or negative mode, to define the desire image. Typical examples of such teaching will be found in Spitzer, U.S. Pat. No. 865,276; Ross, U.S. Pat. No. 2,094,432; Van Natter, U.S. Pat. No. 3,205,155; and Mesley, U.S. Pat. No. 3,642,476.
Unfortunately, from an artistic point of view, all of the known methods providing etched ornamentation yield sharply defined outlines with no contrast gradations as would be provided in a photographic-print-quality image. Most such etched ornamentation provides imagery which may be best defined as analogous to silhouettes of the objects depicted.
Cheney in U.S. Pat. No. 2,036,021, issued March, 1936, teaches the manufacture of ornamental coated glass articles. His teachings are directed to methods for obtaining sharply defined outlines of the image depicted by preventing undercutting of the etched surface by the etchant materials employed.
While not an etching process per se, Harmon in U.S. Pat. No. 1,971,261, issued Aug. 21, 1934, teaches a method for making ornamental mirrors wherein the ornamentation is presented in a contrasting color to that of the background mirrored surface. Thus, Harmon coats a transparent base material wih a photo resist, uses a photographic negative to impress a latent image on the photo resist, and then develops the photo resist in a staining developer bath. The photo resist remaining depicts the image transferred from the photographic negative in the color infused into the developing bath. A silver or other precipitated coating is then deposited over the photo resist image to produce a mirror on which the photo resist imagery may be viewed through the transparent base material.
In an attempt to achieve contrast gradations throughout the etched ornamental imagery, Ko et al in U.S. Pat. No. 2,731,333 issued Jan. 17, 1956, teaches a method whereby two or more metal layers are deposited on a non-metal base. Each metal layer differs from the others in color and etching characteristics. A plurality of etching operations permits etching through different layers of the metals to provide a picture of contrasting colors produced by the differing colored metal layers exposed.
Perhaps the ultimate in approaching photographic quality of ornamentation is approached by Mason et al in U.S. Pat. No. 4,253,910, issued Mar. 3, 1981, which discloses an ornamental mirror and apparatus and method for making same. Here, the metallic metal backing of the mirror is etched to produce a clear, non-reflective area in the transparent base material of the mirror. This area defines the outline of an ornamental object. An actual image of the object so outlined is then positioned so as to be viewed through the resultant transparent area so outlined. The reproduction may be applied to the transparent base by a silk screen process or by the mere imposition of a photographic image which is viewed through the transparent base material of the mirror.
None of the methods known for producing etched ornamental imagery provides an etching of photographic-print-quality having a range of image contrast gradations throughout.
It is therefore an object of the present invention to produce etched imagery of such photographic-print-quality.
It is a specific objective of the invention to provide the methodology whereby an etchable surface may be etched to produce a photographic-print-quality image having a range of image contrast gradations throughout.
It is a particular object of the invention to provide articles of manufacture comprising etched photographic imagery produced by the methods disclosed.